草种混播技术在草坪建植中的应用

探讨了 2个混合草种在上海的引种适应性 ,3年的试验结果表明 ,混合草种的密度、绿度、抗热性均优于单一草种 ,具有更好的综合表现 ,更强的抗逆性 ,适于在草坪建植中应用。     

黄金芽遮阴及返黄的生理生化特性研究

为探究不同光照强度对黄金芽遮阴及返黄生理生化特性的影响,通过遮阴处理,对黄金芽遮阴前和遮阴后一芽二叶叶片的色素物质、叶绿体结构和生化成分进行分析。结果表明,叶绿体内的结构差异、基粒片层的发达程度与叶绿素含量变化一致,表明叶绿体结构影响色素含量与黄化过程。遮阴后,叶绿素a、叶绿素b含量极显著增加(p<0.01),其中处理A叶绿素a增加了8.71倍;整个试验过程氨基酸含量减少,茶多酚、可溶性糖含量均增加,处理A和处理C黄酮含量变化显著增加,水浸出物含量无明显变化。“黄金芽”叶色变异的遮阴时间在两个月以上,返黄时间一个月以上。     

Oxidative damage in forage rape (Brassica napus L.) seeds following heat stress during seed development

A short period (240°C hr; Tb = 25°C) of heat stress (30°C day/25°C night) during forage rape (Brassica napus L.) seed development or at seed physiological maturity can reduce seed vigour, but the extent of oxidative damage associated with this short heat stress was not known. Heat-stressed seeds were assessed for malondialdehyde (MDA) content, hydrogen peroxide (H₂O₂) accumulation, antioxidant enzyme activity, adenylate energy charge and seed ultrastructural integrity, and compared with that of non-heat-stressed seeds. Heat stress increased both MDA content and H₂O₂ accumulation by 35%–50%, reduced antioxidant enzyme activity by between 12% and 67%, and significantly reduced adenosine energy charge. Transmission electron microscope images showed clear evidence of seed deterioration in heat-stressed seeds, including ruptures in cell wall and plasma membranes, fused lipid bodies and damaged mitochondria. Heat stress at physiological maturity caused more oxidative damage than the same heat stress during seed development. Seed vigour decreased as H₂O₂ accumulation increased and antioxidant enzyme activity decreased, but no direct relationship between lipid peroxidation and seed vigour was established. The extent of damage resulting from even shorter periods of heat stress (<240°C hr) before or at seed physiological maturity requires investigation.     

水稻黄绿叶突变体ygl3的鉴定与基因功能分析

[目的]为了丰富和加深人们对植物叶色形成的分子机理认识,对水稻黄绿叶突变体ygl3(yellow green leaf 3)进行表型鉴定和基因克隆,阐明YGL3的分子功能,为解析YGL3调控水稻叶色形成的分子机理奠定基础.[方法]从水稻中花11 CRISPR-Cas9敲除突变体库中鉴定出2份稳定遗传的等位黄绿叶突变体,...     

红外辐射对胡萝卜切片脱水作用机制研究

为揭示不同形态的水在胡萝卜干燥过程中的迁移机制,探明不同形态水在干燥过程中的相互作用和相互转化关系,利用低场核磁共振技术对自由水、不易流动水和结合水3种形态水的分布和迁移规律进行分析.研究表明,在干燥前期主要脱除的是自由水,在干燥后期主要脱除的是结合水;在干燥前期,有少量的自由水向结合水转变,说明在此期间有细胞生命活动...     

A rice geranylgeranyl reductase is essential for chloroplast development

Chloroplasts are essential for plant photosynthesis and growth. Many genes have been identified that regulate plant chloroplast development. However, it is not known at a molecular level how these genes regulate chloroplast biogenesis. In this study, we isolated a mutant ygl2(yellow-green leaf2) that exhibited a pigment-defective phenotype. YGL2 encodes a geranylgeranyl reductase, and in mutant ygl2, there was a single base change(T1361 G) located in the third exon of YGL2 that resulted in a missense mutation(L454 R) in the encoded product. Transmission electron microscopy revealed that chloroplast development was impaired in the ygl2 mutant. The expression levels of plastid-encoded genes were significantly altered in the ygl2 mutant. Furthermore, in a yeast two-hybrid assay, we found that YGL2 interacted with the RNA editing factor MORF8.     

Seasonal variations in the morphology of the seminal vesicles of the African straw-coloured fruit bat (Eidolon helvum)

The study investigated seasonal changes in the morphology of the seminal vesicles of Eidolon helvum in a typical African tropical environment. Seminal vesicles of forty-eight bats were examined during the early rainy, late rainy and peak dry seasons, using gross anatomical, histological and ultrastructural techniques. The interlobular connective tissue septa from the external capsule demarcated the glandular parenchyma into numerous lobules of tubulo-alveolar glands. A simple cuboidal epithelium of mono- or bi-nucleated cuboidal cells lined the glandular mucosa during the rainy season. This was replaced by a bistratified cuboidal epithelium, whose upper layer of cells showed evidence of degeneration, during the dry season. The PAS-positive secretory products appeared to be numerous during the rainy season, but few and clumped together during the dry season. The mean gross weight, interlobular septal thickness, acini diameter and epithelial height of the glands varied significantly with season. Ultrastructural features of the secretory cells during the rainy season showed well-developed cytoplasmic organelles, numerous electron lucid secretory vesicles and electron-dense granules. Secretory epithelial cells of the seminal vesicles are very active during the rainy season, while regeneration of degenerated epithelium in preparation for the next reproductive cycle occurs during the dry season.     

Histomorphological,ultrastructural and morphometrical age-related changes of fundic region of New Zealand rabbits (Oryctolagus cuniculus)

This study investigated the histomorphological, ultrastructural and morphometrical postnatal developmental changes in the rabbit fundic region, especially during changing of the feeding intake. Seventy-two New Zealand rabbits (V-Line breed) at the ages of 1, 7, 15, 23, 30 and 60 days were obtained for light and electron microscopy and morphometric studies of the fundic region. The newborn rabbit's fundic wall was thin and organized into mucosa, submucosa, musclosa and serosa, with a significant increase in thickness with ageing. The fundic glands were few at the first week of life, then increased in length and diameter compared to the preceding age with prominent zonation at 23 days. The gastric pits appeared wide and deep at the first week of life then became typically narrow and shallow at the third week. The mucous cells were the main cell types lining the fundic glands in the first week of life. These cells showed remoulding with a marked increase in Periodic Acid–Schiff reactivity with age. Parietal cells were differentiated earlier (on the first day of life) than the chief cells and distributed at the neck and basal zones. Chief cells differentiated at 15 days old at the base of the glands, followed by an increase in the number and activity. Few active enteroendocrine cells were first seen at 15 days old and then widely distributed throughout the glands. Conclusion: Pronounced histomorphological changes in the fundic mucosal layer, especially the surface and glandular epithelium, correlate with the postnatal rabbit-feeding intake changes.